Detachable lever locking devices for electric switches



R. E. LARKlN May 12, 1959 DETACHABLE LEVER LOCKING DEVICES FOR ELECTRICSWITCHES 3 Sheets-Sheet I 1 Filed Feb. 15, 1956 a a M? an an 1 I W u mNw fl -II n l 8 5% nu I 7 0M M2 R. E. LARKIN DETACHABLE LEVER LOCKINGDEVICES FOR ELECTRIC SWITCHES Filled Feb. 15, 1956 I5 Sheets-Shqet 2 May12, 1959 R. E. LARKIN 5 5 DETACHABLE LEVER LOCKING DEVICES FOR ELECTRICSWITCHES Filed Feb. 15, 1956 5 Sheets-Sheet 3 66 IHA'" II- 67 1 III/IIA- IHIII' United rates Patent DETACHABLE LEVER LOCKING DEVICES FORELECTRIC SWITCHES Robert E. Larkin, Milwaukee, Wis, assignor to Cutler-Hammer, Inc., Milwaukee, Wis., a corporation of Deltaware ApplicationFebruary 15, 1956, Serial No. 565,648 14 Claims. (Cl. 74-536) Thisinvention relates to improvements in detachable lever locking devicesfor electric switches, wherein the lever is to be retained in at leastone position thereof until moved or released from such position by theoperator; and particularly to locking devices including multiple sets ofdifferent cap parts which can be readily changed, and variouslycombined, for retaining the lever in a number of different combinationsof desired positions, without requiring dismounting of the switchitself.

Electrical switches, such as those used on aircraft, are frequently of amulti-position type with a single operating lever to be manually movedto various positions relative to other switch parts and to the panel onwhich the switch is mounted. The lever positions should be readilychangeable by the operator, but also the lever should be restrainedagainst accidental undesired or inadvertent movement, due to shock orvibration or to action of the operator, from a locked position in whichit has been placed by the operator. Under other conditions it is desiredthat the lever automatically return to a given position from one of theother positions and be locked in the return position. Where automaticlever movement is desired, it should be limited to only a preselectedamount and with reference to a predetermined sequence of positions. Inany of the above cases it is desired that the lock be positive andsecure against shock and vibration and that the lever be incapable ofaccidental movement, or inadvertent or thoughtless operation, or anexcessive amount of movement, such as overtravel.

It is therefore an object of the present invention to provide novel,improved, and less expensive locking means for a lever operable to aplurality of positions and which positively prevents accidental orinadvertent movement of the lever from a locked position to anotherposition thereof.

Another object of the invention is to provide a locking device for theoperating lever of a multi-position switch in which various lockingparts are interchangeable and can be assembled for locking the lever ineach of the switch positions or in only one or more of such positons.

Another object of the invention is to provide a locking device formulti-position switches, in which the number of parts and the weight ofthe device are reduced as compared with prior devices for the samepurpose.

Another and more specific object of the invention is to increase thesize of the operating lever of a multi-position switch of the characteraforementioned, while retaining the possibility of mounting the switchin a standard size hole in a panel or other suitable support.

Another object of the invention is to minimize entry of moisture anddust into enclosed parts of such a switch, by providing for drainage ofsuch foreign matter from around the outer end of the passage through thebushing for the lever of the switch, and by sealing the space betweenthe lever and the peripheral wall of such passage.

Another object of the invention is to provide locking devices for theoperating levers of multi-position electrical switches of the characteraforementioned, which preserves 2,885,905 Faten'ted May 12, 1959 "icevisibility of the panel on which the switches are mounted andcorrespondingly conserves space on such panel.

Other objects and advantages of the invention will appear hereinafter,in connection with the accompanying drawings illustrating certainembodiments of the invention and which will now be described, it beingunderstood that the embodiments shown are susceptible of variousmodifications without departing from the spirit and scope of theappended claims.

In the drawings, Figure l is a front elevation of a locking device for aswitch operating lever which is adapted for manual oscillatory movementinto and out of any one of three predetermined positions, in which itmay be locked, for operating an electric switch, a fragmentary portionof which is illustrated; and the lever being shown locked in itsintermediate position.

Fig. 2 is a longitudinal sectional view on the center line of a portionof the structure, looking in the same direction as in Fig. 1, on asomewhat larger scale, and with the lever in and locked in itsright-hand extreme position.

Fig. 3 is a view partially in longitudinal central section, at rightangles to the view of Fig. 2, and partially in elevation, with the leverin the intermediate position shown in Fig. 1.

Fig. 4 is a horizontal sectional view, taken on the line 44 of Fig. 1,looking in the direction of the arrows, and showing the means forlocking the lever in any one of its three predetermined positions.

Fig. 5 is a side elevational view of the upper section of the cap shownin Fig. 4.

Fig. 6 is a horizontal sectional view, taken substantially on the planeof line 6-6 of Fig. 1, looking in the direction of the arrows.

Fig. 7 is a top plan view of coacting portions of one pair of capmembers, which when assembled on a bushing and clipped together areadapted to provide for locking of the lever only in the intermediate oneof its three operative positions.

Fig. 8 is a view similar to Fig. 7 providing for locking of the leveronly in the upper end position thereof, and leaving the lever unlockedin its intermediate or mid-position and in the lower end position towhich it may be moved.

Fig. 9 is a view similar to Fig. 7 providing for locking of the leveragainst movement fromits intermediate position toward its lower endposition, but permitting relatively free manual movement of the leverfrom its intermediate position to its upper end position.

Fig. 10 is a view similar to Fig. 7, but providing for locking of thelever in each of its upper and lower end positions, and leaving thelever unlocked in the intermediate position thereof.

Fig. 11 is a view similar to Fig. 7, but showing means adapted for usewith a two-position switch, in which the lever is adapted to be lockedin either position.

Fig. 12 is a view, partially in elevation and partially in section on alongitudinal central plane, illustrating a modified form of the presentinvention in which the lever is automatically returned to anintermediate position from one end position, but locked againstautomatic return from its other end posit-ion.

Fig. 13 is a top plan View of the coacting cap portions of the locking.device of Fig. 12 which provides for locking of the lever in the lowerend position and in the intermediate position of a multi-positiondevice; to which intermediate position it is automatically returned fromits upper end position upon manual release of the switch lever.

Fig. 14 is a view similar 'to Fig. 13, showing a threeposition type ofswitch, but providing for lockingof the ,lever only in its intermediateposition; to which it is automatically returned from either of its endpositions upon manual release of the switch lever; and

Fig. is a view similar to Fig. 13 but providing for locking of the leveronly in one of its two operative posiing of the switch lever in any oneof three positions. A n etal member 21 of inverted U- or saddle-shape isattached to the switch housing 16 in a well known manner and has itscentral portion formed with an apertured boss, as shown, against thelower surface of which the reduced end of the tubular bushing 22 isadapted to be upset, for attachment of said parts to each other.

Bushing 22 is shown in Fig. 2 as being substantially cylindrical, and isinitially externally threaded to the upper end thereof for projectionoutwardly through a panel or other suitable support (not shown) formounting therein. The bushing22 has a longitudinal external keyway 33for receiving suitable means for predetermining the rotary position ofthe bushing relatively to the metal member 21 and for other purposes. Aninternal shoulder 24 is formed in bushing 22 toward the end thereofremote from the switch casing 16 and said bushing is externallyperipherally grooved at 25 adjacent such end. An external flange 25 isthus formed adjacent the upper end of the bushing and such flange isalso externally threaded. The bushing is of such length that washers,seal rings and two nuts can be placed thereon for mounting on the usualpanel of up to one-eighth inch thickness. The switch casing 16, coverplate 17 and bushing 22 may be con sidered as coacting to form mountingmeans for the lever 18.

The lever 18 has an enlarged portion 27 which is within the bushing 22when the parts are in their assembled relation, such portion being atthe lever fulcrum point within the bushing. One surface 28 of theenlarged lever portion 27 is in the form of a segment of a sphere formovement 7 of the upper end of lever portion 27 in bearing engagementwith the bushing shoulder 24 when the lever is oscillated in the passagethrough which it extends into the switch casing. A somewhat wedge-shapedgroove is provided in the lever portion 27 to receive an annular member29. The member 29 is preferably formed of a resilient rubber orrubber-like material not substantially affected by heat, vapors, etc.,which may be present where the switch is to be used; and its innerdiameter is of a size to grip the inner periphery of the groove in thelever while its outer diameter is of a size to seat at its outer edgeagainst the inner peripheral surface of the bushing 22. The resilientmember 29 is preferably under slight compression between the lever 18and the bushing 22 and is of a thickness to permit lateral flexing inthe lever groove without bodily shifting as the lever is oscillated.Therefore member 29 forms a seal effectively to prevent passage ofmoisture or other foreign matter through the bushing into the switchcasing 16.

Generally similar parts 35 and 36 engage and extend about the flange 25of the bushing and engage in the groove 25 formed therein, to form a capfor the end of the bushing; and such parts 35 and 36 provide anelongated opening therethrough, as shown in Fig. 4, whereby the lever 18may be oscillated into either of two end positions and through anintermediate position, in respect of a switch of the three-positiontype. The cap members 35 and 36 are held in place by a one-pieceresilient metal. clip 37 of a generally inverted cup shape but having a.

multiplicity of resilient fingers 38 respectively adapted to snapinwardly over a downwardly facing shoulder 39 on the cap members andbearing inwardly against the peripheral portions of the respective capmembers beneath such shoulder. The cap parts 35, 36 are shown as formedto jointly provide three downwardly extending notches 40, 41, 42 (seeFig. 4) respectively adjacent the two ends of and centrally of theopening through the cap. Such sets of notches coact for jointlyproviding the two end positions and an intermediate position of thelever when the parts 35 and 36 are used. The several other cap portionsare hereinafter described in further detail.

The lever 18 is formed with a pair of flanges 46, 46 between theenlarged portion 27 thereof and the outer end of the lever; said flangescooperating with the straight walls of the elongated central opening inthe cap to prevent rotation of the lever. A washer 47 is attached to theouter end of the lever 18 as by riveting over an integral extension 48of lever 18. Washer 47 extends beyond the cross sectional area of thelever to serve as a downwardly facing flange at said end of the lever. Asleeve 50 is placed about the lever 18 and has external threads at theupper end thereof for cooperatively engaging the threads formed in a nutor knob 51 capping the sleeve and enclosing the end of the lever. Sleeve50 is provided with a pair of diametrically opposed slots 50 and 50extending downwardly from the upper end of said sleeve. As shown in Fig.3 washer 47 is provided with a pair of lugs 47 and 47 which are adaptedto fit into said slots 58 and 50 so that when washer 47 is rigidlyattached to the upper end of lever 18 sleeve 50 will be positively heldagainst rotation with respect to said lever. The nut 51 is preferably ofsubstantially greater external diameter than the sleeve 50 to providesurfaces which may be gripped by the operators fingers for retraction ofsleeve 50 from a locked position thereof.

The sleeve 50 is of larger internal diameter than the external diameterof the upper end portion of lever 18 and has an internal flange 52 atthe lower end thereof to form a seat for one end of a helicalcompression spring 53, which bears at its other end against the lowersurface of washer 47. Sleeve 50 also has a pair of integral downwardlyextending substantially triangular projections 54 located at degreesspacing from each other and adapted for engagement in the cap notches(40, 41 and 42 of Fig. 4, for example) depending upon the position ofthe lever. The sleeve sub-assembly 5054 may be considered as aretractable lever member or portion which is external of the mountingmeans and coacts with the cap assembly for such purposes as will now bedescribed.

Referring particularly to Figs. 3, 4 and 5, the cap parts 35 and 36 !aregenerally similar but the cap portion 35 has an inwardly projecting keyportion 58 to enter the bushing keyway 33 for preventing rotation of theentire cap and one-piece clip assembly with respect to the bushing 22,whereas the cap portion 36 has no such key. For any given combination oflever positions in which it is desired to lock the lever 18, the caphalves 35, 36 coact to provide notches, as shown at 40, 41, 42 (orone-half of ta notch 41 when the division line between the cap partsfalls within the notch). Each coacting pair of notch parts in the leapare in alinement so that the sleeve teeth 54 may simultaneously enterinto a pair of the notches; the notches extending at a right angle tothe direction of movement of the lever 18. Passages or slots 59 extendthrough each cap part from the inside to the outside surfaces thereoffor drainage of moisture or foreign matter carried thereby, and whichwould otherwise accumulate in the cap and tend to drain into the innerportion of bushing 22, and thence into the switch casing 16.

There is no substantial wear upon the cap parts, and such parts cantherefore be made as die castings of relatively soft metal. Unless theoperator exerts a pull upon the sleeve unit 50-54 the spring 53 willremain in its expanded condition, with the respective teeth 54 biasedinto one of the sets of notches to a sufiicient extent to restrain thelever against movement out of a given position pending manual retractionand movement of the lever 18 to another position.

In operation, therefore, the operator must grip the sleeve-cap handleunit 50, 51 and exert a pull thereon longitudinally of the lever 18 tocompress the spring 53 sufiiciently to raise the teeth 54 out of thethen engaged set of notches. After the teethhave been disengaged from anotch, the lever 18 may be moved to any other position provided for by alocking cap unit, such as menn bers 35, 36 and clip 37 (in Fig. 1),according to the functions to be afforded by the particular switch.

The cap parts 35, 36 shown in Figs. 1 through 6 jointly providethreesets of notches whereby the lever may be locked in either of twoendpositions or in an intermediate position. Such cap construction isaccordingly particularly useful where a three-position switch is usedand the switch is to be locked in each one of its three positions.

The combinations of pairs of cap parts shown in Figs. 7 to 11,inclusive, are likewise adapted to be assembled with respect to abushing like the bushing 22 aforedescribed and with respect to the lever18 as aforementioned, and to be held in assembled relationship by theone-piece resilient metal clip member 37 shown in Figs. 1 to 3,inclusive, and in Fig. 6.

The lower cap part 104 shown in Fig. 7 is identical with thecorresponding cap part 104 in Fig. 9; whereas the upper cap part 105 inFig. 7 is different from all the other cap parts herein illustrated. Thecap parts of Fig. 7 are adapted formse with a switch actuating leverlike that shown in Figs. 1 to 3; but in which said. lever may be lockedonly in its intermediate, or ofl, position, as indicated by the recesses1114 and 1115 forming the intermediate cavity 106. It is to beunderstood that in each form of the invention herein disclosed theswitch parts themselves (other than the locking means therefor) may bearranged to normally provide for. automatic spring return of theoperating lever from one extreme position to the intermediate position(as shown in Fig. 12), or from either extreme position to saidintermediate position; or *from one extreme position to the other in atwo-- position type of switch; different forms of such momentary typesof switch actuators being well known to those skilled in this art.

The upper cap part 187 in Fig. 8 is combined with a lower cap part 108,for use with a three-position switch having an intermediate ofiposition, and an on position at each extreme or end position of thelever. lever (not shown) may be biased in any well known manner toreturn to its intermediate or oil? position at the midlength oi the slot1118 when the lever is manually released from its extreme position 108or when said lever is manually released after withdrawal of its lockinglugs or cars from the end locking cavity designated by the numenal 107The cap parts 104 and 109 in Fig. 9 are respectively recessed asindicated at 1114 1414* and at 109 1119 for cooperation with the leverlugs, to normally lock the lever against movement firom its intermediateposition to its lower extreme position in the slot 109 1414 pendingmanual withdrawal of the lever lugs (54, 54, shown in Fig. 3) fromengagement with the lower end walls 16 2 1M of the opposite portions ofrecess 1114*, 1134 On the contrary the switch lever 18 is relativelyfreely movable from its intermediate ofl position to its upper extremeposition, with reference to Fig. 9, because of the relatively largersize orwidth of the recess portions 109 the bottoms of which extendentirely to the aforementioned recesses liM 1114 The cap parts 107 and110 in Fig. 10 are recessed adjacent opposite end portions of the slotaffording clearance for movement of the lswitch lever; such recessesbeing designated by the numerals 107 1117 and 111%,

'ihe

1 of the lever out of one extreme position and movement thereof to itsother extreme position.

The cap parts 111 and 112 of Fig. 11 are respectively formed to providea relatively short clearance slot 113 for the switch lever; it beingunderstood that when the switch lever is adjacent the upper end wall ofslot 113 it will be locked in position, preferably the off position ofthe switch mechanism, by engagement of the lever projections 54, 54 withthe walls of the cavities formed at 111 111 and 112 112 formed at themeeting surfaces of the respective icap parts 111 and 112.

Oap part 112 in Fig. 11 and cap part 32 in Fig. 13 are respectivelyshown as being identical with the cap part 36 in Fig. 4, and are. shownas provided adjacent the lower end of the slots 113 (Fig. 11) and 113(Fig. 13) for the switch lever with a pair of recesses 112 112, Fig. 11,and 87,87, Fig. 13, which are adapted to receive the projecting lugs onthe switch lever to lock the same in its lower extreme position; whichmay, for example, with respect to Fig. 11, 'be presumed to be the singleon position, of the switch.

The modified forms of my invention as illustrated in Figs. 12 through 15in general include the locking device features previously described,together with means for automatically insuring return of the lever to anintermediate position upon manual release thereof from one extremeposition (Figs. 12 and 13); or from either extreme position to anintermediate position (Fig. 14); or from one of its extreme positions tothe other, in a twoposition switch (Fig. 15); the die-cast cap partsbeing formed so as to facilitate operation of the return means.

A metal support member 66 (Fig. 12) is formed to provide space betweenthe cover member 17 for the insulating switch housing 16 and the metalsupport member 66 to which a plate 67 or the like is attached. Plate 67serves as attaching means or as abutments for opposite ends 68 of aspring wire having two spaced helically wound, portions, one of which isshown at 68 said Wire having a normally straight portion 68 between thehelical portions which continuously bears against the switch lever 69 totend to return the level to its intermediate position, as illustrated.

The lever 69 is formed with a ball-like enlargement 70 and has atransverse aperture :for receiving a pivot pin 71. A bushing 74 is fixedin the opening in the metal support member 66 and is formed with akeyway 7'5 and an upper end flange 76 and is externally threaded formounting upon a supporting panel, as aforedescn'bed. The interior of thebushing 74 is formed with its opposite end portions of substantiallyfiusto-conical contour, and with an intermediate cylindrical portion 77.A resilient, elastic, rubber or rubber-like sealing member 78 is formedas a short cylinder with an internal ball-shaped recess; the wallportions of which are adapted to grip the lever portion 70; and havingintegral external peripheral flanges at the ends to seat against theinner cylindrical surface 77 of the bushing for thereby sealing thelever in the bushing. The upper end portion of lever 69 carries thesleeve-nut unit 5ll54 previously described.

Bushing 74 is capped by two generally similar cap parts 81, 82 which arejointly of generally disk-like shape and coacting to define an elongatedopening therethrough for accommodating the upper end portion of lever69. Each cap part is formed with an internal flange to engage thebushing 74 under the upper end flange 76 thereof and the cap part 81 hasa key 83 engageable in the keyway of the bushing to prevent rotation ofthe assembled cap parts relatively to the bushing '74. The cap parts areheld in position by a punched and stamped resilient sheet metal clip 84which is preferably the same as the clip 37 aforedescribed, and whichcoacts with the present cap parts in the same manner as previouslydescribed. The cap parts 81, 82 are likewise shaped to be engaged by andto hold sleeve teeth 54. As shown in Figs. 12 and 13, holding surfaces87 are formed adjacent the right-hand end (Fig. 12) of the clearanceOpening through the cap parts and another pair of holding surfaces 88are formed intermediate the ends of said cap opening. The cap surfacesbetween the pair of holding surfaces 88 and the left-hand end of the capopening are smooth curves and are designated 90 and 91 (see Fig. 13).Hence voluntary locking of the lever 69 is possible in the presentconstruction either at the right-hand end position 87 (Fig. 13) or atthe intermediate position designated 88 (when moving lever 69 from theend position 87).

If the handle unit 50, 51 of lever 69 is manually released aftermovement of said handle to its extreme lefthand position (Fig. 12) thespring 68 acts in an obvious manner to bias lever 69 toward theintermediate position thereof shown in Fig. 12. At the same time thecoiled compression spring 53in handle 50, 51 (see Fig. 2) biases theteeth 54 of sleeve 50 against the downwardly curved cam surfaces 90 and91 (Figs. 12 and 13) to assist in rapidly returning lever 69 to theintermediate position thereof shown in Fig. 12.

The cap of Fig. 14 comprises an upper part 81 (like the upper part 81shown in Fig. 13) and a lower part 89, and has notches 93 only at theintermediate position while the cap surfaces are curved from the outerend positions toward the notches 93 so that the spring 53 within sleeve50 (see Fig. 2) causes the teeth 54 to act against the pairs of camsurfaces 90, 91 or 97, 97 to automatically return or assist in returningthe lever 69 to its intermediate (locked) position from either endposition.

With cap parts like those shown in Fig. 14 it is to be understood thatthe single spring 68 of Fig. 12 might, under proper conditions, beomitted, or an additional spring, like 68, might be mounted on theleft-hand side of lever 69. The circuits can therefore be closed in theend positions only so long as the lever 69 is held therein by theoperator.

The cap parts 98 and 99 shown in Fig. provide holding surfaces ornotches 100 at one end of the cap opening only and said cap parts havemated, continuously upwardly curved surfaces 101, 101 joining thelocking end position 100 with the other end position 103 for the lever.Therefore the upper end of lever 69 may now be locked only by thecooperating pairs of surfaces designated by the numeral 100, and will bereturned automatically to its extreme right-hand position (withreference to Fig. 12) by the action of spring-pressed teeth 54 (as shownin Fig. 12) against the spaced sets of cam surfaces 101, 101 shown inFig. 15, unless the upper end of lever 69 is held in the aforementionedextreme left-hand end position by the operator. With a cap like thatshown in Fig. 15 a spring like that shown in Fig. 12 may not berequired; or, if employed, it should act to automatically throw thelower end portion of the lever 69 to its extreme left-hand position.

I claim:

1. In a detachable locking device of the character described, incombination, an externally threaded tubular metal bushing having aninner end portion of reduced diameter, said bushing having an externalkeyway formed therein and extending inwardly from the outer end thereofwhereby the inner end portion thereof may be rigidly and non-rotatablyattached to a switch housing, said bushing also having a peripheralgroove formed therein spaced inwardly from the outer end thereof, alever positioned within said bushing and adapted for pivotal movementrelatively thereto, means for positively limiting said lever to pivotalmovement in a single plane, said means comprising a cooperating pair offormed metal members, each of said members having an inwardly projectingpor- .tion adapted to fit closely within the peripheral groove in saidbushing, said formed metal members when jointly assembled on saidbushing being adapted to completely surround the same, and a singlepunched and stamped resilient sheet metal member adapted to be pressedinwardly over said formed metal members jointly, said sheet metal memberhaving a multiplicity of resilient lugs formed thereon for snapengagement with the inner surfaces of said formed metal members jointly,whereby the latter are positively retained in assembled relation to eachother and to said bushing by said sheet metal member.

2. The combination according to claim 1, wherein one of said formedmetal members is provided with an integral inwardly projecting lugadapted to fit closely within said keyway, whereby said formed metalmembers are jointly retained in a fixed position relatively to saidbushing.

3. The combination according to claim 1, wherein said plurality offormed metal members are die castings of semi-circular contour and areretained in assembled relationship to each other only by said singlepunched and stamped resilient sheet metal member.

4. The combination according to claim 1, wherein said formed metalmembers are provided on opposite sides of the plane of pivotal movementof said lever with pairs of integral, transversely aligned, raised andindented portions of like contour, said lever having a retractablehandle portion normally spring biased inwardly toward said formed metalmembers for cooperation therewith to positively retain said handle in atleast one of a plurality of different angular positions, but subject torelease from such position upon manual outward movement of said handle.

5. The combination according to claim 1, wherein said formed metalmembers are provided on opposite sides of the plane of pivotal movementof said lever with two matched groups of transversely aligned, alternateraised and indented portions, said lever having a retractable,plural-toothed handle portion normally springbiased inwardly toward saidformed metal members for cooperation therewith to positively retain saidhandle in at least one position and to insure automatic return of saidhandle to said one position upon release thereof after manual movementthereof to at least one other alternative position.

6. The combination according to claim 1, wherein said formed metalmembers are provided on opposite sides of the plane of pivotal movementof said lever with transversely aligned, pairs of raised and indentedportions of like contour, said transversely aligned pairs of raisedportions being located in alternate relationship to said pairs ofindented portions and being formed integrally with the latter, saidlever having a retractable handle portion normally biased inwardlytoward said formed metal members for cooperation therewith to normallyinsure automatic return of said handle to its intermediate position uponmanual release thereof after manual movement of the same from engagementwith said intermediate pair of indented portions.

7. The combination according to claim 1, wherein the cooperating pair offormed metal members are respectively provided with like inwardlyextending arcuate surfaces so as to insure automatic return of saidhandle to one extreme position, upon manual release thereof aftermovement thereof to its other extreme position.

8. The combination according to claim 1, wherein various individualmembers of the respective pairs may be combined at will to affordvarious functionally different switching control characteristics.

9. In a detachable lever locking device for electric switches and thelike, in combination, an externally threaded tubular metal bushing, ametal lever supported within said bushing for pivotal movement withrespect thereto, a spring-biased retractable hollow handle memberattached to said lever at the upper end of the latter, said handlemember having a pair of oppositely disposed,

inwardly extending, substantially triangular projections at the lowerend portion thereof, for the purpose set forth, means for positivelyinsuring against rotary displacement of said lever relatively to saidbushing, and means rigidly attached to said lever and having slidingengagement with said handle member for insuring against rotarydisplacement of said handle member relatively to said lever.

10. In a detachable lever locking device for electric switches, incombination, an externally threaded hollow metal bushing having areduced inner end portion which is adapted for rigid, non-rotatableattachment to a cooperatively formed sheet metal casing member, thethreaded portion of said bushing having a peripheral groove formedtherein in a plane parallel to and offset inwardly from the outer endthereof, said bushing also having a single, straight line, lateralgroove formed therein and extending throughout the threaded lengththereof in a direction at a right angle to said peripheral groove, and amultiplicity of different lever locking members of outwardly convex,semi-circular peripheral contour adapted for use in pairs selectively,according to the particular controlling functions desired, therespective members of each pair being so formed as to provide fornon-rotatable interlocking engagement thereof jointly with saidperipheral and straight line lateral grooves upon complete assembly ofall parts of the device, and a one-piece punched and stamped resilientsheet metal member having a multiplicity of integral inwardly projectingshouldered lugs formed thereon and insertable simultaneously over saidlever locking members jointly with a snap fit to positively retain thelatter in assembled position, a manually operable lever positionedwithin said bushing and supported for pivotal movement with respectthereto, an inwardly spring-biased retractable handle non-rotatablyattached to the outer end portion of said lever, and said handle havinga pair of transversely spaced, inwardly projecting teeth formed thereonfor cooperation jointly with the pair of lever locking members toprovide for automatic retention of said lever in at least one of aplurality of different positions thereof at will.

11. A device of the character set forth in claim 10, wherein saidone-piece, punched and stamped sheet metal member is provided with arelatively large central opening to afford clearance for said lever,said retractable handle, and said transversely spaced pair of teethformed on the latter.

12. A device of the character set forth in claim 11, wherein at leastone pair of inwardly extending convex cam surfaces are provided upon oneor both of said lever locking members, and wherein associated springmeans are provided for insuring automatic return of the switch lever toa predetermined normal position thereof upon manual release of theswitch handle.

13. A device of the character set forth in claim 12, wherein said meansfor insuring automatic return of the switch lever to a predeterminednormal position thereof includes two laterally spaced parallel pairs ofinwardly curved convex cam surfaces respectively formed on each of theparticular pair of lever locking members aforementioned.

14. For an electric switch operating lever oscillatable in a mountingmember, said lever having an inwardly spring-biased handle portionmanually retractable outwardly with respect thereto, said handle portionhaving a pair of parallel inwardly extending teeth formed thereon at theinner end thereof, a lever lock through which said lever extendscomprising a pair of sections of semi-circular contour jointly affordingan upper surface of a shallow dome shape, said sections jointlyproviding an elongated opening therethrough which extends in a directionat right angles to the line of division therebetween, to thereby provideclearance for movement of said handle from at least one operatingposition thereof to another, at least one of said sections having a pairof recesses formed in the dome shaped upper surface thereof and openingto said elongated opening aforementioned, and said retractable handleportion when withdrawn from locking engagement with the walls of saidpair of recesses being movable manually, or automatically under theinfluence of an associated biasing spring associated therewith, toanother predetermined position thereof, for circuit control.

References Cited in the file of this patent UNITED STATES PATENTS1,988,636 Thomas June 22, 1935 2,223,032 Farmer Nov. 26, 1940 2,246,919Krantz June 24, 1941 2,409,022 Diedring Oct. 8, 1946 2,510,122 LomholtJune 6, 1950 2,723,571 Koenig Nov. 15, 1955 2,759,075 Hults Aug. 14,1956

